build: add ng_package rule for @angular/material

In order to make this work, this includes:
* Move schematics under src/lib
* Change sass rules to omit sourcemaps
* Add cdk/text-field and lib/tree to packages list
* Add bazel rules for prebuilt themes
* Add html assets to all ng_module rules
* Point all ng_module rules to a package common tsconfig
* Add missing index.ts for src/lib
* Add bazel rules for schematics
* Fix incorrect module_name for hyphenated lib ng_module rules
* Add NgModules to `imports` of the example module (formerly were just
exports)

Author: jelbourn

.gitignore

@@ -41,5 +41,5 @@ testem.log
 /.git
 
 # schematics
-/schematics/**/*.js
-/schematics/**/*.map
+/src/lib/schematics/**/*.js
+/src/lib/schematics/**/*.map

BUILD.bazel

@@ -14,12 +14,15 @@ filegroup(
   # TODO(alexeagle): figure out what to do
   srcs = glob(["/".join(["node_modules", pkg, "**", ext]) for pkg in [
     "@angular",
+    "@angular-devkit",
+    "@schematics",
     "@types",
     "bytebuffer",
     "hammerjs",
     "jasmine",
     "minimist",
     "moment",
+    "parse5",
     "protobufjs",
     "protractor",
     "reflect-metadata",